使用display flex在图像顶部垂直对齐引导程序btn

Question

正如我的标题所说，我正在尝试垂直对齐我的btn，使其位于图像的中心。我运气不好，因为我的btn位于我的图像下方，而不是顶部。我试了很多，但似乎都不起作用。我已经发布了我的HTML和CSS，也许有人可以指导我从哪里开始。

HTML

<div class="row">
    <div class="col-md-4">
        <div class="imgAbout">
          <img src="img/team/neil580x410.jpg" class="img-responsive" alt="Neil Elmouchi Bio">
          <a class="btn btn-sm btn-primary" href="bios/teamBioNeil.html" role="button">View More</a>
        </div>
      <h1>Neil Elmouchi</h1>
      <h3>Chairman &amp; CEO<br> 
      Senior Wealth Advisor</h3>
    </div>
</div>

CSS

#about img {
  margin: 0 auto;
}
.imgAbout {
  background: #d5d5d5;
  text-align: center;
}
.imgAbout img {
  opacity: 1;
  transition: opacity .25s ease-in-out;
  -moz-transition: opacity .25s ease-in-out;
  -webkit-transition: opacity .25s ease-in-out;
}
.imgAbout img:hover {
   opacity: 0.4;
}

Answer 1

您感到困惑，因为您忘记了元素通常不能彼此重叠。因此，为了在较大图像的顶部上有一个按钮，我们通常使用叠加（位置：绝对）技术来提高图像维度的灵活性。这是您修改后的示例

.imgAbout {
  position: relative;
}
/* overlay to inherit dimension from imgAbout and centralize button */
.center-container{
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}
.imgAbout img {
  width: 100%;
  height: auto;
  display: block;
  opacity: 1;
  transition: opacity .25s ease-in-out;
  -moz-transition: opacity .25s ease-in-out;
  -webkit-transition: opacity .25s ease-in-out;
}
.imgAbout:hover img {
   opacity: 0.4;
}

https://jsfiddle.net/0bt4q9vk/

Answer 2

要实现预期结果，请使用以下选项

HTML:

<div class="row">
  <div class="col-md-4">
    <div class="imgAbout">
      <img src="http://www.w3schools.com/css/img_fjords.jpg" class="img-responsive" alt="Neil Elmouchi Bio">
      <a class="btn btn-sm btn-primary" href="bios/teamBioNeil.html" role="button">View More</a>
    </div>
    <h1>Neil Elmouchi</h1>
    <h3>Chairman &amp; CEO<br> 
      Senior Wealth Advisor</h3>
  </div>
</div>

CSS：

#about img {
  margin: 0 auto;
}
a{
vertical-align:top;
display:block;
margin-top:-430px
}
.imgAbout {
  background: #d5d5d5;
  text-align: center;
  margin-top:20px;
 }
.imgAbout img {
  opacity: 1;
  transition: opacity .25s ease-in-out;
  -moz-transition: opacity .25s ease-in-out;
  -webkit-transition: opacity .25s ease-in-out;
}

.imgAbout img:hover {
   opacity: 0.4;
}
h1,h3{
  position:relative;
  top:400px;
}

Codepen-http://codepen.io/nagasai/pen/mEpNOY?editors=1111